This invention relates to a cassette loading device for transferring a cassette, containing a magnetic tape, to a cassette loading position where information can be recorded on and reproduced from the magnetic tape.
A conventional, most commonly-used cassette loading device of the aforementioned type is front loading type, wherein a cassette is inserted into an opening, formed in a front panel of a magnetic recording and reproducing device, and is pushed to urge a holder. When the holder is pushed by a predetermined distance, a motor switch is closed to cause a motor to rotate. The driving force of the motor moves the holder horizontally in the same direction as the direction of the cassette insertion, and then moves the holder vertically downwardly, thereby bringing the cassette to a cassette loading position.
In such a front loading-type device, however, the cassette must be inserted horizontally into the narrow opening formed in the front panel, and this is rather inconvenient.
A linear skating type cassette loading device has been proposed in, for example, Japanese Patent Unexamined Publication 2-31363 in which a cassette needs only to be placed on a tray from above the tray. In such a loading device, the tray for supporting the cassette thereon can be projected to a stand-by position disposed forwardly of a front panel of a recording and reproducing device, and the cassette can be placed on the thus projected tray from above the tray. When either pushing the tray or pressing an on-off button, the tray is horizontally transferred by the driving force of a motor, and then the cassette is vertically moved to a cassette loading position.
In a linear skating-type cassette loading device, the cassette is not placed directly on the tray, but is placed on a holder supported on the tray. The drive mechanism is of such a design that the tray is transferred only in the horizontal direction, and after the horizontal transfer of the tray, only the holder is moved vertically.
In this drive mechanism, a rack, formed integrally with the tray, is in mesh with a pinion gear to which the rotational force of the motor is transmitted, so that the cassette is horizontally transferred into a magnetic recording and reproducing device. After the cassette is horizontally moved by a predetermined stroke, the horizontal movement of the cassette is changed into a vertical movement. This vertical transfer of the cassette is driven by an arm swingable in dependence upon a cam groove in the pinion gear.
During the rotation of the motor, the pinion gear is continuously rotated. In order to change the direction of movement of the cassette, it is necessary to release the meshing between the rack and the pinion gear before the horizontal transfer of the cassette is completed. It is desired that immediately after this meshing is released, the cassette begins to move vertically. However, it is impossible to start this vertical movement before the next tooth of the pinion gear is brought into engagement with the tooth of the rack. Therefore, the position of release of the meshing is disposed by a predetermined distance before the point of start of the above vertical movement. Thus, the driving is interrupted during the transfer of the cassette, and this makes the transfer of the cassette unstable.